Fix ExecutionDetails.values type

grafast/grafast/src/engine/executeBucket.ts

@@ -20,6 +20,7 @@ import type {
   ExecuteStepEvent,
   ExecutionDetails,
   ExecutionDetailsStream,
+  ExecutionDetailsValues,
   ExecutionEntryFlags,
   ExecutionExtra,
   ExecutionResults,
@@ -830,7 +831,9 @@ export function executeBucket(
       indexMap: makeIndexMap(count),
       indexForEach: makeIndexForEach(count),
       count,
-      values,
+      values: Object.assign(values, {
+        get: values.at as ExecutionDetailsValues["get"],
+      }),
       extra,
       stream: evaluateStream(bucket, step, distributorOptions),
     };

grafast/grafast/src/interfaces.ts

@@ -720,19 +720,24 @@ export interface ExecutionDetailsStream {
   initialCount: number;
 }
 
+type TupleIndicies<T extends readonly [...any[]]> = {
+  [K in keyof T]: K extends `${infer N extends number}` ? N : never;
+}[keyof T];
+export type ExecutionDetailsValues<
+  TDeps extends readonly [...any[]] = readonly [...any[]],
+> = { [TKey in keyof TDeps]: ExecutionValue<TDeps[TKey]> } & {
+  get<const TKey extends TupleIndicies<TDeps>>(
+    idx: TKey,
+  ): ExecutionValue<TDeps[TKey]>;
+};
 export interface ExecutionDetails<
   TDeps extends readonly [...any[]] = readonly [...any[]],
 > {
   /** The size of the batch being processed */
   count: number;
 
   /** An "execution value" for each dependency of the step */
-  values: {
-    [DepIdx in keyof TDeps]: ExecutionValue<TDeps[DepIdx]>;
-  } & {
-    length: TDeps["length"];
-    map: ReadonlyArray<ExecutionValue<TDeps[number]>>["map"];
-  };
+  values: ExecutionDetailsValues<TDeps>;
 
   /** Helper; makes array from `callback(batchIndex)` for each `0 <= batchIndex < count` */
   indexMap: IndexMap;

grafast/grafast/src/steps/listTransform.ts

@@ -253,7 +253,7 @@ export class __ListTransformStep<
       );
     }
 
-    const listStepValue = values[this.listStepDepId];
+    const listStepValue = values[this.listStepDepId as 0];
 
     if (itemStep._isUnary) {
       const list = listStepValue.unaryValue();

grafast/grafast/src/steps/listen.ts

@@ -68,15 +68,15 @@ export class ListenStep<
     values,
     stream,
   }: ExecutionDetails<
-    readonly [GrafastSubscriber<TTopics>, TTopic]
+    readonly [GrafastSubscriber<TTopics>, TTopic, TTopics[TTopic] | undefined]
   >): GrafastResultStreamList<TTopics[TTopic]> {
     if (!stream) {
       throw new Error("ListenStep must be streamed, never merely executed");
     }
     const pubsubValue = values[this.pubsubDep as 0];
     const topicValue = values[this.topicDep as 1];
     const initialEventValue =
-      this.initialEventDep !== null ? values[this.initialEventDep] : null;
+      this.initialEventDep !== null ? values[this.initialEventDep as 2] : null;
     return indexMap((i) => {
       const pubsub = pubsubValue.at(i);
       if (!pubsub) {